definition: growth in the pituitary gland, which is a small organ, about the size of a pea, in the center of the brain just above the back of the nose. Most pituitary tumors are benign, although they frequently produce too many hormones, which can cause problems in other parts of the body. Symptoms may include headaches, vision problems,, nausea, vomiting or any of a fairly wide range of symptoms, which depend on the type of pituitary tumor. Diagnostic procedures include lab tests for hormone levels, a CT scan, and MRI. Treatment used is surgery, although transphenoidal hypophysectomy, craniotomy, or radiation therapy may be used, as well as certain drugs that block the pituitary from making too many hormones. (en)number: singularpart of speech: nounreliability code: 10term type: main entry term